The women's hammer throw event at the 2004 World Junior Championships in Athletics was held in Grosseto, Italy, at Stadio Olimpico Carlo Zecchini on 13 and 14 July.
| Gold | Mariya Smolyachkova | |
| Silver | Yang Qiaoyu | |
| Bronze | Laura Gibilisco |
14 July
| Rank | Name | Nationality | Attempts | Result | Notes | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | 2 | 3 | 4 | 5 | 6 | ||||||||
| align=left | align=left | | 66.81 | x | x | x | 64.49 | x | 66.81 | ||||
| align=left | align=left | | 59.67 | 61.67 | 60.12 | 60.13 | 61.67 | x | 61.67 | ||||
| align=left | align=left | | 60.95 | x | x | x | 54.90 | x | 60.95 | ||||
| 4 | align=left | align=left |  | x | 60.74 | x | x | x | 51.79 | 60.74 | |||
| 5 | align=left | align=left |  | 59.61 | 58.35 | x | x | 60.37 | 53.11 | 60.37 | |||
| 6 | align=left | align=left |  | x | 60.18 | 55.80 | 58.31 | 58.09 | x | 60.18 | |||
| 7 | align=left | align=left |  | x | 58.59 | x | x | x | 57.09 | 58.59 | |||
| 8 | align=left | align=left |  | 57.41 | x | 57.45 | 56.50 | 56.59 | 57.32 | 57.45 | |||
| 9 | align=left | align=left | | x | x | 57.32 | 57.32 | ||||||
| 10 | align=left | align=left | | 54.98 | 53.71 | 55.55 | 55.55 | ||||||
| 11 | align=left | align=left |  | x | 53.61 | 54.53 | 54.53 | ||||||
| 12 | align=left | align=left | | 53.76 | 52.91 | x | 53.76 | ||||||
13 July
| Rank | Name | Nationality | Attempts | Result | Notes | |||||
|---|---|---|---|---|---|---|---|---|---|---|
| 1 | 2 | 3 | ||||||||
| 1 | align=left | align=left | | 60.11 | 64.35 | - | 64.35 | Q | ||
| 2 | align=left | align=left | | 60.36 | 54.53 | 56.12 | 60.36 | q | ||
| 3 | align=left | align=left | | 60.04 | x | x | 60.04 | q | ||
| 4 | align=left | align=left | | 58.18 | 59.70 | x | 59.70 | q | ||
| 5 | align=left | align=left | | 59.65 | 55.95 | 57.45 | 59.65 | q | ||
| 6 | align=left | align=left | | x | x | 57.85 | 57.85 | q | ||
| 7 | align=left | align=left | | 56.61 | x | 52.12 | 56.61 | q | ||
| 8 | align=left | align=left | x | x | 55.60 | 55.60 | ||||
| 9 | align=left | align=left | 54.90 | x | 53.68 | 54.90 | ||||
| 10 | align=left | align=left |  | x | 52.55 | x | 52.55 | |||
| 11 | align=left | align=left | 52.13 | x | 52.10 | 52.13 | ||||
| 12 | align=left | align=left |  | 40.61 | 51.42 | 50.62 | 51.42 | |||
| 13 | align=left | align=left |  | x | 50.07 | x | 50.07 | |||
| align=left | align=left |  | x | x | x | NM | ||||
| Rank | Name | Nationality | Attempts | Result | Notes | |||||
|---|---|---|---|---|---|---|---|---|---|---|
| 1 | 2 | 3 | ||||||||
| 1 | align=left | align=left | | 60.47 | x | x | 60.47 | q | ||
| 2 | align=left | align=left | | 59.91 | 60.38 | 60.06 | 60.38 | q | ||
| 3 | align=left | align=left | | x | x | 59.01 | 59.01 | q | ||
| 4 | align=left | align=left | | 54.19 | 57.09 | 53.50 | 57.09 | q | ||
| 5 | align=left | align=left | | 55.26 | 56.69 | x | 56.69 | q | ||
| 6 | align=left | align=left | | x | 55.91 | 56.14 | 56.14 | |||
| 7 | align=left | align=left | 52.58 | 55.86 | x | 55.86 | ||||
| 8 | align=left | align=left | | 52.93 | 55.84 | x | 55.84 | |||
| 9 | align=left | align=left |  | x | 54.90 | 49.12 | 54.90 | |||
| 10 | align=left | align=left | | 54.42 | x | x | 54.42 | |||
| 11 | align=left | align=left |  | 53.10 | 51.41 | x | 53.10 | |||
| 12 | align=left | align=left |  | 48.08 | 47.10 | 52.83 | 52.83 | |||
| 13 | align=left | align=left | 51.53 | 51.69 | 52.23 | 52.23 | ||||
| 14 | align=left | align=left |  | 51.72 | x | x | 51.72 | |||
| 15 | align=left | align=left | x | 51.64 | 46.25 | 51.64 | ||||
According to an unofficial count, 29 athletes from 20 countries participated in the event.